1. Field of the Invention
Embodiments disclosed herein generally relate to a magnetic read head for use in a hard disk drive.
2. Description of the Related Art
The heart of a computer is a magnetic disk drive which typically includes a rotating magnetic disk, a slider that has read and write heads, a suspension arm both above and below the rotating disk and an actuator arm that swings the suspension arm to place the read and/or write heads over selected circular tracks on the rotating disk. The suspension arm biases the slider towards the surface of the disk when the disk is not rotating but, when the disk rotates, air is swirled by the rotating disk adjacent to the media facing surface (MFS), such as an air bearing surface (ABS), of the slider causing the slider to ride on an air bearing a slight distance from the surface of the rotating disk. When the slider rides on the air bearing, the write and read heads are employed for writing and reading magnetic transitions corresponding to host data. The read and write heads are connected to a signal processing circuitry that operates according to a computer program to implement the writing and reading functions.
As written tracks and read heads narrow, read heads become more challenging to fabricate and performance of the heads degrades. One recording system level approach to relaxing the narrow reader and thin read gap requirement is the use of multiple sensors to decode data on the disk. Multiple sensors are a part of an emerging technology called multiple in, multiple out (MIMO) recording systems whereby rather than a single read sensor, multiple sensors are used to improve areal density. The multiple in, multiple out (MIMO) recording system design utilizes multiple read heads to decode the data recorded on the disk.
The MIMO concept typically uses a read head having multiple read sensors to improve the overall performance of the recording system. One type of MIMO system utilizes symmetric side-by-side read sensors, separated by a narrow gap. The side-by-side readers can be used with a Chevron type system as well whereby a third sensor is also present either above or below the side-by-side sensors. If the gap separating the side-by-side sensors is not necessarily centered between them, there is a dramatic impact on the system performance if the misalignment becomes too large (e.g., >10 nm).
Therefore, there is a need in the art for an improved MIMO read head having side-by-side sensors that are properly aligned.